Intraoral dental radiology positioning device

ABSTRACT

A receptor positioning device for taking dental bitewing radiographs of a patient&#39;s teeth comprises a receptor holding member adapted to receive a receptor for exposing x-radiation from the x-ray machine and a collimation plate having a substantially flat surface for aligning with an x-ray machine. The collimation plate has a rectangular opening in its surface for passage of radiation from the x-ray machine to expose a receptor in the receptor holding member and a pair of handles extending away from the plate for positioning the device. The collimation plate is constructed of metal having a thickness of at least 0.075 in., preferably at least 0.100 in., to reduce the passage of radiation from the x-ray machine to the patient except at the plate opening. The device also includes an arm between the collimation plate and the receptor holding member, the arm including a biting surface for engaging the patient&#39;s teeth to secure the device in the patient&#39;s mouth.

This is a continuation of U.S. application Ser. No. 10/395,371 filedMar. 24, 2003, which is a continuation-in-part of U.S. application Ser.No. 10/365,921 filed Feb. 13, 2003, which is a continuation-in-part ofU.S. application Ser. No. 10/113,401 filed Apr. 1, 2002. Thisapplication is also related to an application by the same inventor filedon even date herewith as attorney's docket no. DEDE140001000 entitled“Intraoral Dental Radiology Positioning Device For Use With AimingRing.”

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to devices for dental radiographicprocedures or intraoral diagnostics, and more particularly, to intraoraldental radiology positioning devices relating to positioning x-ray filmor receptors in a patient's mouth during radiographic procedures.

2. Description of Related Art

Intraoral x-ray diagnosis involves positioning an x-ray film within apatient's mouth next to the inner surface of the teeth or bone beingstudied. The film is then exposed to an x-ray beam generated outside themouth and passing through the target. Known intraoral dental radiographytypically employs a dental device having an alignment member includingan x-ray film holding structure at one end, an aligning arm at anotherend, and a bite plate positioned between the ends. The alignment membermay include a collimation structure for collimation of an x-ray beam toconform more accurately to the size and shape of the x-ray film held bythe film holding structure. A commonly prescribed dental radiograph isthe “bitewing”, whereby an image is acquired of the crowns of the teethbiting together and their surrounding socket bone. Also typical is filmmounted in a holder which includes a bite block portion extending fromthe film in the direction of the external x-ray tube. The patient bitesdown on the bite block with the target teeth and holds the film inposition next to the target.

Most dental radiographic techniques utilize beams of circularcross-section despite the fact that the dental films are typicallyrectangular in shape. A disadvantage of known devices is that thecross-sectional area of the beam used by the radiographic technique istypically larger than the surface area of the x-ray film. When thecross-sectional area of the beam does not match the film size, thepatient can be exposed to unnecessary radiation which irradiates tissuesbeyond the borders of the dental film.

Another disadvantage of current x-ray film positioning instruments isthat there can be errors in aiming the x-ray. These errors arefrequently associated with a rectangular position-indicating deviceattached to an x-ray machine. Aiming error exposes the patient toneedless retakes of radiographs. Common film positioning instruments mayalso allow unwanted x-radiation to pass through the receptor, or filmholding element.

Typical film positioning devices and instruments include multiple parts,requiring assembly and adjustment. The multiple arrangements of partsmay lose their set position which can cause a reduction in the sharpnessof the acquired image.

Enhancing the ability to sterilize dental equipment is desirable in thefield.

Current film positioning devices may have disadvantages when sterilizingbecause parts, such as cushioned areas, may be less accessible orreceptive to steam, heat or chemical methods.

Commonly, patients may assist in positioning and holding a filmpositioning device in their mouth. Typical devices may be difficult tograsp and manipulate in the patient's mouth making it problematic forthe patient to assist in positioning the instrument.

Bearing in mind the problems and deficiencies of the prior art, it istherefore an object of the present invention to provide a device whichwill reduce patient exposure of x-radiation.

It is a further object of the present invention to provide a devicewhich will reduce aiming error and cone cuts.

It is another object of the invention to provide a device which willimprove the quality of the acquired image on the receptor-x-ray film.

It is yet another object of the present invention to provide a devicewhich will universally adapt to traditional film and electronic/digitalreceptors.

It is a further object of the present invention to provide a devicewhich will minimize movement of the interconnected parts of the deviceonce the parts are desirably positioned.

It is another object of the present invention to provide a device whichminimizes movement of the device in the patient's mouth.

It is yet another object of the present invention to provide a devicewhich fixedly sets the x-ray source to align with the receptor, or film.

It is a further object of the present invention to provide a devicewhich limits magnification and keeps magnification uniform.

It is another object of the present invention to provide a device whichmaximizes sharpness of the acquired image on the film.

It is a further object of the present invention to provide a devicewhich facilitates sterilization.

It is another object of the present invention to provide a device whichis of maximum durability.

It is yet another object of the present invention to provide a devicewhich minimizes patient discomfort and malpositioning.

It is a further object of the present invention to provide a devicewhich minimizes “retakes” of radiographs.

It is another object of the present invention to provide a method ofpositioning a film-positioning device in a patient's mouth providing anunobstructed line between an x-ray device and x-ray film.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

SUMMARY OF THE INVENTION

The above and other objects, which will be apparent to those skilled inart, are achieved in the present invention which is directed to, in afirst aspect, a receptor positioning device for taking dental bitewingradiographs of a patient's teeth, which comprises a receptor holdingmember adapted to receive a receptor for exposing x-radiation from thex-ray machine and a collimation plate having a substantially flatsurface for aligning with an x-ray machine. The collimation plate has anopening in its surface, preferably rectangular, for passage of radiationfrom the x-ray machine to expose a receptor in the receptor holdingmember and a handle extending away from the plate for positioning thedevice. The collimation plate is constructed of metal having a thicknessof at least 0.075 in., preferably at least 0.100 in., to reduce thepassage of radiation from the x-ray machine to the patient except at theplate opening. The device also includes an arm connecting thecollimation plate and the receptor holding member, the arm including abiting surface for engaging the patient's teeth to secure the device inthe patient's mouth.

In a related aspect, the present invention is directed to a method fortaking dental bitewing radiographs of a patient's teeth comprisingproviding a receptor positioning device of the type described above, andproviding a receptor on the receptor holding member. The method thenincludes positioning the receptor holding member in the patient's mouthand the patient's teeth on the biting surface to secure the device inthe patient's mouth, adjusting the position of receptor positioningdevice by grasping the handle extending from the collimation plate,aligning an x-ray machine with the substantially flat surface of thecollimation plate, and passing radiation from the x-ray machine throughthe opening of the collimation plate while substantially blockingpassage of radiation through the collimation plate thickness to exposethe receptor.

The device preferably includes a pair of handles extending from thecollimation plate, which handles may be opposite each other. The methodthen includes grasping the handles to adjust the position of receptorpositioning device.

In another aspect, the present invention is directed to a receptorpositioning device for taking dental bitewing radiographs of a patient'steeth comprising a collimation plate defining a substantially centralopening. A receptor holding member is adapted to receive a receptor, andan elongated arm including a biting surface is positioned toward adistal end thereof. The elongated arm is adapted to receive and coupleat a first end to the collimation plate. The elongated arm is designedand adapted to extend towards and couple to a rear portion of thereceptor holding member, opposite the collimation plate, such that anunobstructed path is defined between the substantially central openingof the collimation plate and the receptor received by the receptorholding member. The receptor holding member may preferably accommodate aplurality of receptor dimensions, films, and digital receptors. In apreferred embodiment of the present invention, the collimation plate,the receptor holding member, and the elongated arm are rigidly fixedtogether. In another preferred embodiment of the present invention, thecollimation plate, the receptor back plate, and the elongated arm areconstructed of metal.

In a related aspect, the present invention is directed to a receptorpositioning device for taking dental bitewing radiographs of a patient'steeth, which comprises a collimation plate having an opening therein foraligning an x-ray machine and a receptor holding member adapted toreceive a receptor for exposing x-radiation from the x-ray machine. Anelongated arm is coupled at a first end to the collimation plate andincludes a biting surface positioned toward a distal end thereof. Theelongated arm from the biting portion distal end further extends towardsthe collimation plate and is coupled to the receptor holding member,such that an unobstructed path is defined between the substantiallycentral opening of the collimation plate and the receptor received bythe receptor holding member while the patient's teeth engage the bitingportion distal end.

The biting portion distal end on the elongated arm, adjacent thereceptor back plate, may include an incompressible receiving portionadapted for biting with the patient's teeth. Optionally, the bitingportion distal end includes an elastomeric impression material adaptedfor creating and registering with an occlusion pattern of the patient'steeth. Openings in the biting portion distal end permit the elastomericimpression material to couple to the distal end surface.

The collimation plate may include handles opposite of one another forthe patient to grasp. The opening in the collimation plate is preferablysubstantially rectangular in shape, is orientated similarly to the filmhaving a substantially rectangular shape, and the substantially centralopening defined by the collimation plate is adapted to corresponddimensionally to the dimensions of the receptor. Preferably, thecollimation plate is constructed of metal having a thickness of at least0.075 in. to prevent overexposing the patient to needless additionalradiation.

In another related aspect, the biting surface is adjacent to thereceptor holding member such that the receptor is positioned behind thepatient's teeth. The receptor holding member may include notches in anedge for receiving at least one band to secure together the receptor andholding member. Where the receptor is a digital receptor having a datacord, there may be further included a connector securing the data cordto the elongated arm between the collimation plate and the receptorholding member.

In another aspect of the present invention, a receptor positioningdevice for taking dental bitewing radiographs of teeth inside apatient's mouth, comprises a rigid, fixed structure including acollimation plate defining a substantially rectangular opening, areceptor holding member adapted to receive a receptor, and an elongatedarm being adapted to receive and couple at a first end to thecollimation plate. The elongated arm is designed and adapted to extendtowards and couple at a second end to a rear portion of the receptorholding member, opposite the collimation plate, such that anunobstructed path is defined between the substantially rectangularopening of the collimation plate and the receptor received by thereceptor holding member. A biting surface is fixedly attached to adistal end of the elongated arm and adjacent to the receptor holdingmember such that the receptor is positioned behind the teeth on whichthe radiographs being taken while the biting surface is gripped by teethon the opposite side of the patient's mouth.

In yet another aspect of the present invention, a method for takingdental bitewing radiographs of a patients' teeth comprises initiallyproviding a receptor positioning device of the type describe above.Preferably, the device is a rigid, fixed structure including acollimation plate defining a substantially central opening, a receptorholding member adapted to receive a receptor, and an elongated arm beingadapted to receive and couple at a first end to the collimation plate.The elongated arm is designed and adapted to extend towards and coupleto a rear portion of the receptor holding member such that anunobstructed path is defined between the substantially rectangularopening of the collimation plate and the receptor received by thereceptor holding member. A biting surface is provided which is fixedlyattached to a distal end of the elongated arm and adjacent to thereceptor holding member such that the receptor is positioned behind thepatient's teeth on which the radiographs is being taken while the bitingsurface is gripped by teeth on the opposite side of the patient's mouth.The patient's teeth bite on the biting surface such that an unobstructedx-ray path is defined between the collimation plate and the receptorreceived by the receptor holding member. An x-ray machine is alignedwith the opening of the collimation plate, and the receptor is exposedsuch that x-radiation from the x-ray machine passes along theunobstructed path defined between the collimation plate and thereceptor.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention believed to be novel and the elementscharacteristic of the invention are set forth with particularity in theappended claims. The figures are for illustration purposes only and arenot drawn to scale. The invention itself, however, both as toorganization and method of operation, may best be understood byreference to the detailed description which follows taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a perspective view of the receptor positioning device of thepresent invention.

FIG. 2 is a front elevational view of the collimation plate of thedevice shown in FIG. 1.

FIG. 3 is a side elevational view of the receptor positioning deviceshown in FIG. 1 depicting the position of the patient's teeth.

FIG. 4 is another side view of the receptor positioning device shown inFIG. 1 rotated 180° from the view in FIG. 3.

FIG. 5 is a side elevational view of the elongated arm of the receptorpositioning device shown in FIG. 1.

FIG. 6 is a side view of the elongated arm of FIG. 5.

FIG. 7 is a side elevational view of another embodiment of an elongatedarm of the receptor positioning device shown in FIG. 1

FIG. 8 is a side view of the elongated arm of FIG. 7.

FIG. 9 is a front elevational view of another collimation plate for usewith the receptor positioning device shown in FIG. 1 having arectangular hole of different dimensions.

FIG. 10 is a front elevational view of another collimation plate for usewith the receptor positioning device shown in FIG. 1 having arectangular hole of still different dimensions.

FIG. 11 is a side view of the receptor positioning device shown in FIG.1 depicting the patient's teeth biting the device and the x-ray machinein position.

FIG. 12 is a back plate for receiving receptor of the receptorpositioning device shown in FIG. 1.

FIG. 13 is a side elevational view of the back plate of FIG. 12.

FIG. 14 is another embodiment of a back plate for receiving electronicreceptors of the receptor positioning device shown in FIG. 1, havingopposing notches.

FIG. 15 is a side elevational view of the back plate of FIG. 14.

FIG. 16 is a perspective view of the receptor positioning device of thepresent invention incorporating a digital receptor.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

In describing the preferred embodiment of the present invention,reference will be made herein to FIGS. 1-16 of the drawings in whichlike numerals refer to like features of the invention. Features of theinvention are not necessarily shown to scale in the drawings.

A preferred embodiment 10, shown in FIGS. 1-6 and 11, depicts theintraoral dental radiology receptor positioning device of the presentinvention. Referring to FIGS. 1-4, the receptor positioning deviceincludes a substantially flat collimation plate 12, having a surfacearea 14. The surface area 14 defines a substantially central rectangularopening 16. The collimation plate 12 further includes opposing elongatedhandles 18 extending outward on opposite sides thereof. The receptorpositioning instrument 10 further includes an elongated arm 20 and afilm or electronic receptor holding member 28 having a back plate 30 andclips 32 for holding x ray film or electronic receptors. The elongatedarm 20 is connected at a bent first end 40 to the back of thecollimation plate 50, preferably, by welding or other rigid connection.The elongated arm further includes a second end 22 attached to the rearsurface 52 of the back plate 30 of the receptor holding member 28,opposite collimator plate 12.

The film or electronic receptor holding member 28 back plate 30 ispreferably of metal and the opposing clips 32 are designed and adaptedto receive and grasp a removable film or digital-electronic receptor 54.The elongated arm 20 includes a flat upper surface 26 adapted to receivea patient's teeth. The patient's teeth 60 a on one side of the mouth arepositioned to grip the substantially flat biting surface 26 of theelongated arm 20, as shown in FIG. 3. The biting surface receivingportion is normally incompressible. Optionally, biting surface 26 on arm20, behind the receptor plate 54, includes a plurality of circularperforations or openings, for example the three 6 mm diameter openings70 longitudinally spaced 8 mm apart as shown in FIG. 3. These openingsaccommodate a curable elastomeric impression material 72, on either sideof biting surface 26 (see also FIGS. 4-6, which may be used to createand register with the unique occlusion pattern of the patient's teeth,as also shown in FIG. 11. This registration may be removed, archived andreused to create reproducible x-ray images of the teeth in repeatedsequential exposures over time.

The film or receptor 54 held on the back plate 30 by the clips 32 of thereceptor holding member 28 is positioned behind the desired teeth 60 bto be exposed, on the opposite side of the patient's mouth. Preferably,the back plate 30 and receptor 54 are parallel to collimation plate 12.The film or receptor 54 is thereby positioned to be exposed to an x-rayfrom the x-ray machine 62 to show the condition of teeth 60 b, as shownfurther in FIG. 11.

Referring to FIG. 2, the collimation plate 12 further includes apreferably rectangular opening 200 positioned substantially in thecenter of the collimation plate 12. The opening 16 has a verticaldimension 202, and a horizontal dimension 204. In the preferredembodiment shown in FIGS. 1 and 2, the vertical dimension 202 of theopening is about 1.210 inches, and the horizontal dimension 204 ispreferably about 1.552 inches. The collimation plate 12 is adapted toaxially align the x-ray machine's position indicating cylinder device 62with the receptor 54, as shown by the x-ray centerline 63. It does thisin two ways. First, the x-ray machine is easily centered because the twodevices, 12, 62, have substantially the same diameter. Axial offsetwould be apparent by extension of the outer edge of collimation plate 12beyond the outer rim of the x-ray machine position indicating cylinderdevice 62. Second, substantially full, flat contact of the collimationplate 12 with the x-ray machine's position indicating cylinder device62, as shown in FIG. 3, would assure optimal alignment of the x-rayreceptor with the x-ray beam.

The orientation and size of the rectangular collimation openingdescribed above is for use with the adult size horizontal bitewingradiographic examination of patients with normal anatomy and dentitions.Other sizes may be made for small children or for other uses. Whileexisting commercially available metal collimation plates generally haveon the order of 0.050 in. thickness, the inventor's dosimetry studieshave shown that this thickness still permits a substantial amount ofradiation to penetrate and expose the patient to needless additionalradiation. Preferably, the thickness T of the collimation plate (FIG. 4)has at least 0.075 in. thickness, more preferably 0.080 or 0.100 in. ormore to block such excess radiation.

Referring to FIGS. 5 and 6, the substantially flat elongated arm 20 ofthe preferred embodiment shown in FIG. 1 is shown including the firstend 40, the second end 22, a short member 23 (on which biting surface 26is located) having a first length 25, and an angled portion 21. FIG. 5shows arm 20 as a flat blank prior to forming at the dotted lines, whileFIG. 6 shows arm 20 after forming, where both ends 22 and 40 are bentapproximately 90°. The second end 22 of the elongated arm 20, and theouter edge of the angled portion 21 define a first dimension 27. Thefirst dimension 27 is preferably about 1.25 inches, and the first length25 is preferably about 2.54 inches. The outer edge of the short member23 and the vertical plane define an angle 29 which determines theangulation of the short member 23 of the elongated arm 20. The preferredangle 29 is about 12°. These dimensions and angles are preferred forthree reasons. First, the dimension of the elongated arm is consistentwith optimal placement of an x-ray receptor in mouths with normalanatomy and dentitions ranging in size from that of a child (8 years andup) to very large. Second, the dimension of the elongated arm iscompatible with accommodating conventional film and digital-electronicreceptors currently available. Third, the dimension of the elongated armis compatible with accommodating the x-rays machine's positionindicating cylinder device in optimal configuration with the receptor inthe patient's mouth.

Referring to FIGS. 7 and 8, another embodiment of an elongated arm 100is shown which can be used with the receptor positioning device 10 shownin FIGS. 1-4. The elongated arm 100 includes the first end 40, thesecond end 22, the angled portion 21, and the short member 23 as in theembodiment shown in FIGS. 5 and 6. Again, FIG. 7 shows arm 20 as a flatblank prior to forming at the dotted lines, while FIG. 8 shows arm 20after forming, where both ends 22 and 40 are bent approximately 90°.However, here the short member has a second length 106 which is morethan the dimension 25 of the embodiment shown in FIGS. 1 and 5-6. Thesecond length 106 is preferably about 2.85 inches. The second end 22 ofthe elongated arm 20, and the outer edge of the angled portion 21 definea second dimension 104 which is less than the first dimension 27 of theembodiment shown in FIGS. 1 and 5-6. The second dimension 104 is lessthan the first dimension shown in FIG. 5 and preferably about 1.10inches. The outer edge of the short member 23 and the vertical planedefine an angle 108 which is less than or more acute than the angle 29of the embodiment shown in FIGS. 5 and 6 and is preferably about 7°. Themore acute angle 108 better accommodates deep overbite occlusions. Thisother embodiment of the elongated arm has a dimension that is easilyaccommodated in mouths that have anatomy with deep overbites(retrognathic mandibles) ranging in size from that of a child to a largeadult.

Referring to FIGS. 9-10, other embodiments of a collimation plate 12 areshown including opposing elongated handles 18. Referring to FIG. 9, thecollimation plate 12 further includes a preferably rectangular opening210 positioned substantially in the center of the collimation plate 12,where the length of the opening 210 is smaller than the width. Theopening 210 has a vertical dimension 212, and a horizontal dimension214. In this embodiment, the vertical dimension 212 of the opening ispreferably about 1.552 inches, and the horizontal dimension 214 ispreferably about 1.210 inches. This embodiment offers a differentpositioning of the opening to correspond to an adult receptor or filmheld in the receptor holding member 28. The orientation and size of therectangular collimation opening is for use with the adult size verticalbitewing radiographic examination. This is useful for observingcompromised dentitions (with large restorations and height of alveolarcrest bone decreased by marginal periodontal disease) that would not bevisualized on horizontal bitewing images.

Referring to FIG. 10, the collimation plate 12 further includes apreferably rectangular opening 220 positioned substantially in thecenter of the collimation plate 12. The opening 220 has a verticaldimension 222, and a horizontal dimension 224. In this embodiment thevertical dimension 222 of the opening is about 1.000 inch, and thehorizontal dimension 224 is preferably about 1.552 inches. Thisembodiment is designed to correspond to a child's receptor or film heldin the receptor holding member 28. The size and orientation of therectangular collimation opening is for use for horizontal bitewingexaminations in small children (4-8 years) and very small adults oradults with limited ability to open their mouths.

Referring to FIGS. 12 and 13, the back plate 30 is shown of the deviceof FIG. 1. FIG. 12 shows the flat blank for plate 30 and FIG. 13 showsplate 30 after forming. The back plate 30 includes the clips 32 andpreferably has an overall length 36 of about 1.71 inches, and adimension between the clips 38 of preferably about 1.578 inches, as theyare shown formed and curled in FIG. 13. The preferred dimension 34between the back plate 30 and the formed clip 32 is about 0.05 inches.The overall length 36 of the back plate 30 with the clips 32 curled, asshown in FIG. 13, is preferably about 1.71 inches, and the length 38between the curled clips 32 is preferably about 1.578 inches. The width35 of the back plate 30 is preferably about 1.20 inches. The dimensionsherein accommodate standard intraoral dental film.

Referring to FIGS. 14 and 15, another embodiment is shown of the backplate 30. As before, FIG. 14 shows the flat blank for plate 30 and FIG.15 shows plate 30 after forming. The embodiment shown in FIGS. 14 and 15is the same as in the embodiment shown in FIGS. 12 and 13 except in theaddition of two opposing notches 39. These notches are on opposite sidesof the back plate and are on adjacent sides with reference to the clips32. The notches 39 are a specified dimension 31 from the midpoint of thelong side of the back plate 30. The dimension 31 is preferably about0.15 inches. The notches 39 accept electronic receptors to the backplate 30 of the receptor holding member 28 with the aid of orthodonticelastics (not shown). The overall length 36, the length 38 between thecurled clips 32, and the width 35 of the back plate 30 is the same as inthe previous embodiment shown in FIGS. 12-13. FIG. 16 shows receptor 54held in place on receptor holding member 28 by a pair of orthodonticelastic bands 76 which are received in two spaced pairs of notches 39.Where the receptor 54 is a digital-electronic receptor, data cord 78extending from the receptor may be secured to and along elongated arm 20by connector 80, between the collimation plate and the receptor holdingmember, so that data plug 82 may be positioned outside the patient'smouth.

Other back plate sizes may be used, such as one designed for receptorsor film used for children which is smaller than the films used with theback plates shown in FIGS. 12-15. Such a back plate would preferablyhave a length between the curled clips of about 1.60 inches long similarto the embodiments shown in FIGS. 12-15, but, a width of preferablyabout 1.00 inches wide to accommodate size film designed for children.

In operation and use, referring to FIG. 11, the patient's mouth 65 isoutlined and the patient's teeth are above and below the elongated arm20 of the receptor positioning device 10. Teeth 60 a bite down on andgrip biting portion 26 of arm 20. Biting portion 26 may containelastomeric impression material which conforms to the occlusion patternof the patient's teeth 60 a. The receptor holding member 28 ispositioned behind the teeth 60 b to be exposed (on the opposite side ofthe mouth from teeth 60 a) and the collimation plate 12 is positioned inadjacent to the patient's mouth 65 and teeth 60 b. The x-ray machine 62is positioned to take an x-ray in front of the collimation plate 12 andexpose the x-ray film receptor 54. If necessary, the patient orradiographer may use handles 18 to reposition the receptor positioningdevice for better comfort or aim. Preferably the collimation plate 12 isconstructed of a metal and rigidly and fixedly fashioned. The rigid andfixed construction of the receptor positioning device 10 provides themost accurate film exposure because there is minimal opportunity forunwanted movement after positioning the device. The metal collimationplate having a rectangular opening 16 reduces patient exposure byabsorbing approximately 50% of primary beam x-radiation for the mostcommonly prescribed dental radiograph, which is the bitewing. Further,the metal collimation plate reduces aiming error, that is, “cone cuts”,which are frequently associated with the rectangular position-indicatingdevice attached to the x-ray machine. Further, the use of thecollimation plate of the present invention having a rectangular opening16 reduces patient exposure to x-radiation by eliminating needless“retakes” of radiographs. The collimation plate 12 of the presentinvention is compatible with typical round (typically 2.75 in. diameter)indicating cylinder device that is typically standard on dentalradiographic machines.

Another advantage of a device of the present invention pertains to theabsorption of x-rays by the metal receptor holding member 28 whichimproves the quality of the acquired image on the film 54. The receptorholding member 28 is preferably constructed of a metal. The metalreceptor holding member 28 will further reduce patient exposure tox-radiation by absorbing x-radiation that would ordinarily pass throughthe receptor or film 54. Also, the metal receptor holding member 28reduces additional secondary or “scatter” radiation that causesdegradation of the image.

As shown in FIGS. 1-16, the unitary design of the receptor positioningdevice 10 eliminates movement of multiple parts which could interferewith the exposure of the film 54. Further, the unitary design sets afixed x-ray source-to-object distance and an object-to-film distance.Another advantage of the unitary design is the maintenance of uniformmagnification and maximization of the sharpness of the acquired image.Another advantage of the receptor positioning device 10 is the preferredall metal design provides a rigid device which is also durable and lendsitself to sterilizing using steam, heat or chemical methods. Moreover,the handles 18 which are part of the collimation plate 12 enables thepatient to handle the device minimizing patient discomfort andmalpositioning.

While the present invention has been particularly described, inconjunction with a specific preferred embodiment, it is evident thatmany alternatives, modifications and variations will be apparent tothose skilled in the art in light of the foregoing description. It istherefore contemplated that the appended claims will embrace any suchalternatives, modifications and variations as falling within the truescope and spirit of the present invention.

1. A receptor positioning device for taking dental bitewing radiographsof a patient's teeth, which comprises: a receptor holding member adaptedto receive a receptor for exposing x-radiation from the x-ray machine; acollimation plate having a substantially flat surface for aligning withan x-ray machine, an opening in the plate surface for passage ofradiation from the x-ray machine to expose a receptor in the receptorholding member, and a handle extending away from the plate forpositioning the device, the collimation plate being constructed of metalhaving a thickness of at least 0.075 in. to reduce the passage ofradiation from the x-ray machine to the patient except at the plateopening; and an arm between the collimation plate and the receptorholding member, the arm including a biting surface for engaging thepatient's teeth to secure the device in the patient's mouth.
 2. Thedevice of claim 1 wherein the collimation plate has a thickness of atleast 0.100 in.
 3. The device of claim 1 including a pair of handlesextending from the collimation plate.
 4. The device of claim 3 whereinthe handles are opposite each other.
 5. The device of claim 1 whereinthe opening in the collimation plate is rectangular.
 6. The device ofclaim 1 wherein the opening in the collimation plate is positionedsubstantially in the center of the collimation plate.
 7. The device ofclaim 1 wherein the opening in the collimation plate is rectangular andis positioned substantially in the center of the collimation plate.
 8. Amethod for taking dental bitewing radiographs of a patient's teethcomprising: providing a receptor positioning device including a receptorholding member adapted to receive a receptor for exposing x-radiationfrom the x-ray machine; a collimation plate having a substantially flatsurface, an opening in the plate surface, and a handle extending awayfrom the plate, the collimation plate being constructed of metal havinga thickness of at least 0.075 in.; and an arm between the collimationplate and the receptor holding member, the arm including a bitingsurface; providing a receptor on the receptor holding member;positioning the receptor holding member in the patient's mouth and thepatient's teeth on the biting surface to secure the device in thepatient's mouth; adjusting the position of receptor positioning deviceby grasping the handle extending from the collimation plate; aligning anx-ray machine with the substantially flat surface of the collimationplate; and passing radiation from the x-ray machine through the openingof the collimation plate while substantially blocking passage ofradiation through the collimation plate thickness to expose thereceptor.
 9. The method of claim 8 wherein the collimation plate has athickness of at least 0.100 in.
 10. The method of claim 8 wherein thedevice includes a pair of handles extending from the collimation plate,and including grasping the handles to adjust the position of receptorpositioning device.
 11. The method of claim 10 wherein the handles areopposite each other.
 12. The method of claim 8 wherein the opening inthe collimation plate is rectangular.
 13. The method of claim 8 whereinthe opening in the collimation plate is positioned substantially in thecenter of the collimation plate.
 14. The method of claim 8 wherein theopening in the collimation plate is rectangular and is positionedsubstantially in the center of the collimation plate.